A Remarkably Useful Sulfur Bridge as Synthetic Lever in an Approach to Javanicin B
作者:Claude Spino、Amélie Dion
DOI:10.3987/com-16-s(s)58
日期:——
A concise and efficient synthesis of a non-racemic advanced intermediate to the quassinoid javanicin B is disclosed. The strategy is centred on a triple diene-transmissive Diels-Alder cycloaddition to form the four rings of javanicin B. A sulfur bridge plays several crucial roles allowing an intramolecular cycloaddition to occur with complete stereoselectivity, controlling the stereochemical outcome of another cycloaddition, and transforming into a pivotal electrophile for the introduction of a particularly hindered methyl group.